In anticipation of trends toward generalism in medicine, the rheumatology community has begun to promulgate guidelines for the management of osteoarthritis (OA). These guidelines emphasize a comprehensive approach toward nonpharmacologic treatment modalities (e.g.., patient education, exercise, social support) and a conservative approach to drug management to minimize the side effects of nonsteroidal antiinflammatory drugs (NSAIDs). Unfortunately, few primary care physicians provide conservative, comprehensive care for OA as promoted in the recent rheumatology literature. Also, while individual elements of a comprehensive approach to OA care have been studied and largely validated in isolation, no research support exists to suggest that better patient outcomes and/or reduced costs of care will result from uniform adoption of OA care guidelines. The specific aim of this project will be to implement, in a controlled fashion, and evaluate a comprehensive plan for the treatment of patients with knee OA by primary care physicians in a managed care environment. Comprehensive care for knee OA will be guided by an algorithm designed to introduce and reinforce (a) an array of nonpharmacologic self-care modalities intended to combat joint pain and preserve function and (b) a stepped protocol for pharmacologic management of knee pain that minimizes the risk of adverse side effects of NSAIDs. Subjects will be 300 patients with a confirmed clinical diagnosis of knee OA who receive their medical care in a large health maintenance organization (HMO) in Indianapolis (i.e., MetroHealth or Indiana University Health Care). Geographically discrete offices of the HMOs will be allocated at random to experimental (OA care by algorithm) or control (routine OA care) conditions (150 subjects/group). Patients who enroll in the study at each location will receive care for knee OA for one year under the guidelines specified by random assignment. Outcomes will be measured at baseline and 3 months, 6 months, 6 months and 12 months after enrollment and will include joint pain, physical function, drug side effects, quality of life (i.e., general health status), satisfaction with OA care, and direct costs of medical care. We hypothesize that comprehensive care, as guided by our algorithms, will result in significant improvement in knee pain, physical function and patient satisfaction, and lower direct costs compared to care delivered under routine circumstances.